LehrerApp/LehrerApp.Desktop.Tests/CompetencyTagGroupBuilderTests.cs

using LehrerApp.Core.Models;
using LehrerApp.Desktop.ViewModels.Groups;
using Xunit;

namespace LehrerApp.Desktop.Tests;

public sealed class CompetencyTagGroupBuilderTests
{
    [Fact]
    public void Build_MarkiertAusgewaehlteItemsAlsSelected()
    {
        var item = new CompetencyItem { Code = "K1", Description = "Erste Kompetenz" };
        var catalog = new List<CompetencyDomain> { new() { Name = "Bereich", Items = [item] } };
        var selected = new List<CompetencyReference> { new() { ItemId = item.Id, Code = item.Code, Description = item.Description } };

        var groups = CompetencyTagGroupBuilder.Build(catalog, selected, _ => { });

        var group = Assert.Single(groups);
        var tag = Assert.Single(group.Items);
        Assert.True(tag.IsSelected);
        Assert.Equal(item.Id, tag.ItemId);
    }

    [Fact]
    public void Build_ReferenzOhneKatalogTreffer_LandetInEigenerGruppeMitMomentaufnahme()
    {
        var catalog = new List<CompetencyDomain>
        {
            new() { Name = "Bereich", Items = [new CompetencyItem { Code = "K1", Description = "Erste Kompetenz" }] },
        };
        var orphaned = new CompetencyReference
        {
            ItemId = Guid.NewGuid(), Code = "ALT1", Description = "Alte, gelöschte Kompetenz",
        };
        var selected = new List<CompetencyReference> { orphaned };

        var groups = CompetencyTagGroupBuilder.Build(catalog, selected, _ => { });

        Assert.Equal(2, groups.Count);
        var fallbackGroup = groups.Single(g => g.Name == "Nicht mehr im Katalog");
        var tag = Assert.Single(fallbackGroup.Items);
        Assert.True(tag.IsSelected);
        Assert.Equal("ALT1", tag.Code);
        Assert.Equal("Alte, gelöschte Kompetenz", tag.Description);
        // Der reguläre Katalog-Bereich bleibt unberührt und zeigt sein einziges Item als abwählbar.
        var catalogGroup = groups.Single(g => g.Name == "Bereich");
        Assert.False(Assert.Single(catalogGroup.Items).IsSelected);
    }

    [Fact]
    public void Build_ToggleAufTag_RuftOnChangedMitDerTagInstanzAuf()
    {
        var item = new CompetencyItem { Code = "K1", Description = "Erste Kompetenz" };
        var catalog = new List<CompetencyDomain> { new() { Name = "Bereich", Items = [item] } };
        CompetencyTag? changed = null;

        var groups = CompetencyTagGroupBuilder.Build(catalog, [], tag => changed = tag);
        var tag = Assert.Single(Assert.Single(groups).Items);
        tag.IsSelected = true;

        Assert.Same(tag, changed);
        Assert.Equal(item.Id, changed!.ItemId);
    }
}